Title: Effect of doping level on high-temperature operation of InAs/GaAs quantum dot infrared photodetectors

Authors: Dong-Bum Seo; Tien Dai Nguyen; Eui-Tae Kim

Addresses: Department of Materials Science and Engineering, Chungnam National University, 220 Gung-dong, Daejeon, 305-764, South Korea ' Department of Materials Science and Engineering, Chungnam National University, 220 Gung-dong, Daejeon, 305-764, South Korea ' Department of Materials Science and Engineering, Chungnam National University, 220 Gung-dong, Daejeon, 305-764, South Korea

Abstract: This study reports the effect of doping level on the performance of InAs/GaAs quantum-dot infrared photodetectors (QDIPs). Two QDIP samples were prepared via molecular beam epitaxy: n+-i(QDs)-n+ QDIP with undoped quantum dot (QD) active region, referred to as undoped QDIP, and n+-n(QDs)-n+ QDIPs intended to contain two electrons per QDs, referred to as doped QDIP. InAs self-assembled QDs were grown on GaAs (001) wafers by three mono-layers of InAs deposition. Both QDIPs showed a photoluminescence peak at 1.182 μm as well as a similar broad photocurrent (PC) spectrum peaked at about 7.5 μm, ranging from 4 μm to 9 μm at 5 K. Undoped QDIP yielded a PC spectrum of up to 100 K, whereas doped QDIP had a PC spectrum of up to 40 K only. This finding was mainly attributed to the lower dark current properties of undoped QDIP. Undoped QDIP at 77 K showed five orders of magnitude lower than the dark current of doped QDIP at 5 K.

Keywords: quantum dots; infrared photodetectors; QDIPs; InAs; indium arsenide; MBE; molecular beam epitaxy; doping levels; high temperature operations; GaAs; gallium arsenide; nanotechnology.

DOI: 10.1504/IJNT.2016.077088

International Journal of Nanotechnology, 2016 Vol.13 No.4/5/6, pp.385 - 391

Published online: 19 Jun 2016 *

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